WhatsApp Data Consumption For Voice Calls & Price
The catch however is that this data comes with an expiry date of about 30 days. So you must consume all of that data within that time-frame.
I also checked the regular voice calling rates offered by Airtel. The regular voice calls are offered at Rs. 1.2 per minute (2 paise per second). We can therefore conclude that if you're using a data plan with a time-limit; the voice calls over whatsapp are cheaper than the regular network calls; but are very costly if you're using the 'on-the-go' plan that doesn't expire.
Tests conducted by AndroidPit showed that on an LTE connection, WhatsApp consumed about 800 KB to 1.3 MB per minute. The data usage also varied upon whether the iOS or Android version was being run; with Android consuming lesser amount of data.
I might have made mistakes in the calculations above (especially with the MB / Mb thing. Do let me know your opinion about WhatsApp Data Consumption and its price as compared to other messengers. Have you performed any such tests on your own?